Two dogsled teams raced across a \(300\)-mile course in Wyoming. Team \(A\) finished the course in \(3\) fewer hours than team \(B.\) If team \(A\)'s average speed was \(5\) mph greater than team \(B\)'s, what was team \(B\)'s average speed in mph?

A. 12
B. 15
C. 18
D. 20
E. 25

The OA is D

Source: GMAT Prep